Substituted alkoxyimino-pyridazones, their manufacture, and their use as herbicides

ABSTRACT

New pyridaz-6-ones having a good herbicidal action, herbicides containing these compounds, and a process for controlling unwanted plant growth with these compounds.

The present invention relates to new and valuable pyridaz-6-ones having a good herbicidal action, herbicides containing these compounds, and a process for controlling unwanted plant growth with these compounds.

The use of 1-phenyl-4-dialkylaminopyridazones and 1-cyclohexyl-4-dialkylaminopyridazones as selective herbicides has been disclosed (German Pat. No. 1,105,232 and German Pat. No. 1,123,510).

We have found that pyridaz-6-one derivatives of the formula ##STR1## where X denotes halogen (Cl, Br), R¹ denotes C₁ -C₆ -alkyl (CH₃, C₂ H₅), R² denotes H, C₁ -C₆ -alkyl (CH₃, C₂ H₅) or haloalkyl (Cl--CH₂), and R³ denotes phenyl or cyclohexyl, exhibit, both pre- and postemergence, a considerable herbicidal action, and do no harm to the crop plants.

The new compounds are prepared by reaction of o-carboxylic acid esters (III) with pyridazone derivatives (II) in the presence of acids, at from 80° to 200° C. The reaction takes place for instance in accordance with the following scheme ##STR2## where X, R¹, R² and R³ have the above meanings.

Examples of acids present during the reaction are phosphoric acid, sulfuric acid, hydrogen halides, organic sulfonic acids, and haloacetic acids. The alcohol R¹ OH formed during the reaction is distilled off from the reaction mixture. In the reaction of II and III to give I, equimolar amounts of II and III, but preferably an excess of III, are used. As solvent, III itself may be used, or all solvents which do not react with III, II or I and have a boiling point higher than R¹ OH, e.g., benzene, toluene, and halobenzenes.

EXAMPLE 1 ##STR3##

230 g of 1-cyclohexyl-5-bromo-4-aminopyridaz-6-one, 1 liter of triethyl o-chloroacetate, and 5 g of o-phosphoric acid were mixed, the mixture was heated to 130° C., and the ethyl alcohol liberated was distilled off from the reaction mixture. The reaction solution was then stirred for 1 hour at 150° C., cooled, and washed with 5% strength aqueous Na₂ CO₃ solution and water; after drying over Na₂ SO₄ the remaining solution was concentrated and the residue recrystallized from petroleum ether. There is obtained 273 g of compound 1; yield: 86%; m.p.: 74°-78° C.

    ______________________________________                                         Calc. C 44.6   H 5.1     N 11.2  Cl 9.44 Br 21.2                               Found C 44.9   H 5.2     N 11.4  Cl 8.9  Br 21.0                               ______________________________________                                    

If 1-phenyl-5-bromo-4-aminopyridaz-6-one is used instead of 1-cyclohexyl-5-bromo-4-aminopyridaz-6-one, the compound ##STR4## is obtained analogously.

The following compounds were prepared analogously:

    ______________________________________                                          ##STR5##                                                                      Compound                                                                       no.     X     R.sup.2 R.sup.1                                                                             R.sup.3                                                                              m.p.(°C.)                              ______________________________________                                         2.      Br    H       C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.11                                                                     95-97                                         3.      Br    CH.sub.3                                                                               CH.sub.3                                                                            C.sub.6 H.sub.11                                                                     100-101                                       4.      Br    CH.sub.3                                                                               C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.11                                                                     60 MHz NMR spectrum                                                            in CDCl.sub.3 (δ values)                                                 1.24 (3H); 1.84 (3H);                                                          1.3-1.7 (10H);                                                                 4.02 (2H); 4.71 (1H);                                                          7.19 (1H)                                     5.      Br    C.sub.2 H.sub.5                                                                        C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.11                                                                     60 MHz spectrum in                                                             CDCl.sub.3 (δ values)                                                    1.01 (3H); 1.24 (3H);                                                          1.3-1.82 (10H);                                                                1.97 (2H); 4.13 (2H);                                                          4.74 (1H); 7.22 (1H).                         6.      Br    H       CH.sub.3                                                                            C.sub.6 H.sub.11                                                                     124-125                                       7.      Br    CH.sub. 2 Cl                                                                           CH.sub.3                                                                            C.sub.6 H.sub.11                                                                     122-125                                       8.      Cl    CH.sub.3                                                                               C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.11                                                                     89-91                                         9.      Cl    C.sub.2 H.sub.5                                                                        C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.11                                                                     270 MHz NMR                                                                    spectrum                                                                       in CDCl.sub.3 (δ values)                                                 1.1 (3H); 1.28 (3H);                                                           1.15-1.95 (10H);                                                               2.2 (2H); 4.3 (2H);                                                            4.95 (1H); 7.5 (1H)                           10.     Cl    H       CH.sub.3                                                                            C.sub.6 H.sub.11                                                                     93                                            11.     Cl    CH.sub.2 Cl                                                                            C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.11                                                                     73-74                                         12.     Cl    H       C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.11                                                                     105-115                                       13.     Cl    H       C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.5                                                                      128-130                                       14.     Br    H       CH.sub.3                                                                            C.sub.6 H.sub.5                                                                      85-88                                         15.     Br    H       C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.5                                                                      113-114                                       16.     Br    CH.sub.3                                                                               CH.sub.3                                                                            C.sub.6 H.sub.5                                                                      98-100                                        17.     Br    CH.sub.3                                                                               C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.5                                                                      57-60                                         18.     Br    C.sub.2 H.sub.5                                                                        C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.5                                                                      78-80                                         19.     Br    CH.sub.2 Cl                                                                            C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.5                                                                      80-81                                         20.     Cl    CH.sub.3                                                                               C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.5                                     21.     Cl    H       CH.sub.3                                                                            C.sub.6 H.sub.5                                                                      102                                           22.     Cl    CH.sub.2 Cl                                                                            C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.5                                                                      84-85                                         23.     Cl    C.sub.2 H.sub.5                                                                        C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.5                                                                      74-77                                         24.     Br    CH.sub.2 Cl                                                                            CH.sub.3                                                                            C.sub.6 H.sub.5                                                                      80                                            25.     Cl    CH.sub.2 Cl                                                                            CH.sub.3                                                                            C.sub.6 H.sub.5                                                                      91-93                                         ______________________________________                                    

The influence of various representatives of the new compounds on the growth of plants is demonstrated in the following experiments.

1. Greenhouse experiments

The vessels employed were plastic flowerpots having a volume of 300 cm³, and which were filled with a sandy loam containing about 1.5% humus. The seeds of the test plants (cf. Table 1) were sown shallow, and separately, according to species. In the case of Cyperus esculentus, pregerminated tubers were used. For the preemergence treatment, the active ingredients were applied to the surface of the soil immediately after the seeds had been shown. The compounds were emulsified or suspended in water as vehicle, and sprayed through finely distributing nozzles. After the agents had been applied, the vessels were lightly sprinkler-irrigated to induce germination and growth and to active the chemical agents. Transparent plastic covers were then placed on the vessels until the plants had taken root. The cover ensured uniform germination of the plants, insofar as this was not impaired by the chemicals.

For postemergence treatment, the plants were first grown to a height of 3 to 10 cm, depending on the growth shape, before being treated. The vessels were not covered after treatment. The pots were set up in the greenhouse-species from warmer areas at from 25° to 40° C., and species from moderate climates at 15° to 30° C. The experiments were run for from 4 to 6 weeks. During this period, the plants were tended and their reactions to the various treatments assessed. The following tables contain the compounds investigated, the application rates in kg/ha of active ingredient, and the plants used for the tests. The scale used for assessment was 0 to 100, 0 denoting no damage or normal emergence, and 100 denoting nonemergence or complete destruction of at least the visible plant parts.

2. Experiments in the open

The experiments were carried out on small plots with loamy sand and loam (pH 5 to 6), the humus content being from 1 to 1.5%. In the preemergence treatment, the compounds were applied either immediately after the crop plants had been sown or up to 3 days thereafter. The crop plants were sown in rows. The weed flora was made up of a wide variety of species, and was natural. The substances were emulsified or dispersed in water as vehicle, and applied by means of a motor-driven plot spray mounted on a hitch. Where no rain fell, artifical irrigation was carried out to ensure germination and growth of the crop plants and weeds. All the experiments were run for several months. During this period, assessment on the 0 to 100 scale were made at certain intervals.

Results

Tables 2, 3 and 4 show the results obtained with the new compounds on grassy and broadleaved unwanted plants. Surgarbeets and sunflowers proved to be crop plants which are not damaged by the active ingredient.

The herbicidal action of the new compounds is so strong that, at higher dosage rates, they completely destroy all herbaceous growth. Possible application areas here are the removal of unwanted plant growth under bushes and trees, and on pathways, squares, playgrounds, etc., and in industrial units and on railroad track.

The tables contain the results obtained on pre- and postemergence treatment. Apart from surface application, the agents may of course also be incorporated into the soil, either before or after sowing, or among already established crop plants. Application techniques may, however, also be used in which the agents are sprayed from suitable spray equipment in such a manner that the leaves of the sensitive crop plants are if possible avoided, and reach the soil surface or unwanted plants growing beneath the crop plants (post-directed, lay-by treatment).

                  TABLE 1                                                          ______________________________________                                         List of plant names                                                                          Abbreviation                                                     Botanical name                                                                               in tables     Common name                                        ______________________________________                                         Alopecurus myosuroides                                                                       Alopec. myos. slender foxtail                                    Beta vulgaris spp.                                                                           Sugarbeets    sugarbeets                                         alt.                                                                           Chenopodium album                                                                            Chenop. album lambsquarters                                                                  (goosefoot)                                        Cyperus difformis                                                                            Cyper. diff.  smallflower                                                                    umbrellaplant                                      Cyperus ferax Cyper. ferax                                                     Datura stramonium                                                                            Dat. stram.   Jimsonweed                                         Digitaria sanguinalis                                                                        Digita. sang. large crabgrass                                    Echinochloa crus galli                                                                       Echino. c.g.  barnyardgrass                                      Euphorbia geniculata                                                                         Euphorb. genic.                                                                              South American                                                                 member of                                                                      the spurge family                                  Helianthus annuus                                                                            Helianth. ann.                                                                               sunflowers                                         Matricaria/Anthemis                                                                          Matric./Anthem.                                                                              chamomile                                          spp.          spp.                                                             Mercurialis annua                                                                            Mercur. annua annual mercury                                     Polygonum spp.                                                                               Polygon. spp.                                                    Sesbania exaltata                                                                            Sesbania exalt.                                                                              hemp sesbania                                                                  (coffeeweed)                                       Sinapis alba  Sinapis alba  white mustard                                      Sinapis arvensis                                                                             Sinapis arv.  yellow charlock                                    Solanum nigrum                                                                               Solanum nigrum                                                                               black nightshade                                   Stellaria media                                                                              Stellaria media                                                                              chickweed                                          ______________________________________                                    

                                      TABLE 2                                      __________________________________________________________________________     Selective herbicidal action of pyridazone derivatives; preemergence            application                                                                    in the open                                                                                    Test plants and % damage                                       Compound        Sugar-                                                                             Alopec.                                                                             Chenop.                                                                              Matric./                                                                              Polygon                                                                            Sinapis                                                                            Stellaria                        no.         kg/ha                                                                              beets                                                                              myos.                                                                               album                                                                               Anthem.spp.                                                                           spp. arv.                                                                               media                            __________________________________________________________________________     1-phenyl-4-dimethyl-                                                           amino-5-chloropyrida-                                                                      1.5 0   8    7    20     0    8   7                                zone-(6)    2.0 --  29   --   28     --   --  10                               prior art                                                                      1-phenyl-4-dimethyl-                                                           amino-5-bromopyrida-                                                                       1.5 --  10   10   5      0    15  15                               zone-(6)                                                                       prior art                                                                      1-phenyl-4-diethylamino-                                                       5-chloropyridazone-(6)                                                                     1.5 0   5    7    7      2    5   7                                prior art                                                                      1-phenyl-4-diethylamino-                                                       5-bromopyridazone-(6)                                                                      1.5 0   15   20   5      0    10  10                               13          1.5 0   --   48   80     --   --  --                                           2.0 0   63   90   77     88   84  97                               14          1.5 2   40   97   100    55   53  80                                           2.0 6   71   92   100    82   84  82                               15          1.5 6   49   81   100    85   55  93                                           2.0 13  73   91   100    94   92  99                               16          1.0 0   70   70   --     --   100 90                                           2.0 0   95   98   78     --   100 87                               17          1.5 0   56   72   98     70   --  64                                           2.0 0   72   86   99     84   80  80                               18          1.0 0   --   51   90     52   26  23                                           2.0 0.4 --   78   98     66   51  53                               19          1.5 0   54   94   100    93   --  82                                           2.0 4   74   98   100    95   --  92                               __________________________________________________________________________      0 = no damage,                                                                 100 = nonemergence, or plants withered                                   

                                      TABLE 3                                      __________________________________________________________________________     Selective herbicidal action of pyridazone derivatives; preemergence            treatment                                                                      in the greenhouse                                                                        Test plants and % damage                                             Compound  Helianth.                                                                           Cyper.                                                                             Digita.                                                                             Echino.                                                                            Euphorb.                                                                            Sesbania                                                                            Sinapis                                                                            Solanum                                                                             Stellaria                       no.   kg/ha                                                                              ann. ferax                                                                              sang.                                                                               c.g.                                                                               genic.                                                                              exalt.                                                                              alba                                                                               nigrum                                                                              media                           __________________________________________________________________________     10    1.0 0    90  100  100 45   98   60  98   30                                    2.0 8    90  100  100 100  100  100 100  100                             6     1.0 10   100 100  75  100  98   100 100  100                                   2.0 15   100 100  80  100  100  --  100  100                             12    1.0 0    100 40   40  40   100  100 100  100                                   2.0 5    100 80   70  100  100  100 100  100                             2     1.0 10   95  95   100 100  100  100 100  100                                   2.0 18   95  95   100 100  100  100 100  100                             3     1.0 0    100 60   100 80   --   98  65   100                                   2.0 0    100 100  100 100  --   98  97   100                             4     1.0 0    100 100  70  100  98   100 100  100                                   2.0 0    100 100  100 100  100  100 100  100                             11    1.0 5    95  --   40  40   98   80  70   --                                    2.0 5    95  90   60  100  100  100 75   100                             1     1.0 2.5  100 100  100 70   100  --  90   --                                    2.0 2.5  100 100  100 100  100  100 100  100                             9     1.0 --   90  80   90  --   80   70  72   --                                    2.0 --   95  100  100 --   100  70  99   100                             5     1.0 5    95  100  --  100  85   100 95   100                                   2.0 15   95  100  100 100  100  100 100  100                             __________________________________________________________________________      0 = no damage,                                                                 100 = nonemergence, or plants withered                                   

                                      TABLE 4                                      __________________________________________________________________________     Selective herbicidal action of further compounds; postemergence                treatment                                                                      in the greenhouse                                                                        Test plants and % damage                                             Compound  Helianth.                                                                           Cyper.                                                                             Dat.                                                                               Digit                                                                              Echino.                                                                            Mercur.                                                                             Sinapis                                                                            Solanum                                                                             Stellaria                         no.   kg/ha                                                                              ann. diff.                                                                              stram.                                                                             sang.                                                                              c.g.                                                                               annua                                                                               alba                                                                               nigrum                                                                              media                             __________________________________________________________________________     6     0.5 0    60  100 --  95  80   100 100  100                                     1.5 10   80  100 100 98  100  100 100  100                               3     0.5 0    92  100  60 80  80   100  75   68                                     1.0 0    92  100  80 93  80   100 100  100                               2     0.5 0    95  100 100 98  100  100  85  100                                     1.0 8    95  100 100 100 100  100 100  100                               __________________________________________________________________________

In view of the many application methods possible, the agents according to the invention, or mixtures containing them, may be used not only on the crop plants listed in the tables, but also in a much larger range of crops for removing unwanted plants. Depending on the object to be achieved, the application rates vary from 0.1 to 15 kg/ha and more.

The following crop plants may be mentioned by way of example:

    ______________________________________                                         Botanical name      Common name                                                ______________________________________                                         Allium cepa         onions                                                     Ananas comosus      pineapples                                                 Arachis hypogaea    peanuts (groundnuts)                                       Asparagus officinalis                                                                              asparagus                                                  Avena sativa        oats                                                       Beta vulgaris spp. altissima                                                                       sugarbeets                                                 Beta vulgaris spp. rapa                                                                            fodder beets                                               Beta vulgaris spp. esculenta                                                                       table beets, red beets                                     Brassica napus var. napus                                                                          rape                                                       Brassica napus var. napobrassica                                               Brassica napus var. rapa                                                                           turnips                                                    Brassica rapas var. silvestris                                                 Camellia sinensis   tea plants                                                 Carthamus tinctorius                                                                               safflower                                                  Carya illinoinensis pecan trees                                                Citrus limon        lemons                                                     Citrus maxima       grapefruits                                                Citrus reticulata                                                              Citrus sinensis     orange trees                                               Coffea arabica (Coffea canephora,                                              Coffea liberica)    coffee plants                                              Cucumis melo        melons                                                     Cucumis sativus     cucumbers                                                  Cynodon dactylon    Bermudagrass in turf                                                           and lawns                                                  Daucus carota       carrots                                                    Elais guineensis    oil palms                                                  Fragaria vesca      strawberries                                               Gylcine max         soybeans                                                   Gossypium hirsutum                                                             (Gossypium arboreum cotton                                                     Gossypium herbaceum                                                            Gossypium vitifolium)                                                          Helianthus annuus   sunflowers                                                 Helianthus tuberosus                                                           Hevea brasiliensis  rubber plants                                              Hordeum vulgare     barley                                                     Humulus lupulus     hops                                                       Ipomoea batatas     sweet potatoes                                             Juglans regia       walnut trees                                               Lactuca sativa      lettuce                                                     Lens culinaris     lentils                                                    Linum usitatissimum flax                                                       Lycopersicon lycopersicum                                                                          tomatoes                                                   Malus pp.           apple trees                                                Manihot esculenta   cassava                                                    Medicago sativa     alfalfa (lucerne)                                          Mentha piperita     peppermint                                                 Musa spp.           banana plants                                              Nicothiana tabacum  tobacco                                                    (N. rustica)                                                                   Olea europaea       olive trees                                                Oryza sativa        rice                                                       Panicum miliaceum                                                              Phaseolus lunatus   limabeans                                                  Phaseolus mungo     mungbeans                                                  Phaseolus vulgaris  snapbeans, green beans,                                                        dry beans                                                  Pennisetum glaucum                                                             Petroselinum crispum                                                                               parsley                                                    spp. tuberosum                                                                 Picea abies         Norway spruce                                              Abies alba          fir trees                                                  Pinus spp.          pine trees                                                 Pisum sativum       English peas                                               Prunus avium        cherry trees                                               Prunus domestica    plum trees                                                 Prunus dulcis       almond trees                                               Prunus persica      peach trees                                                Pyrus communis      pear trees                                                 Ribes sylvestre     redcurrants                                                Ribes uva-crispa                                                               Ricinus communis                                                               Saccharum officinarum                                                                              sugar cane                                                 Secale cereale      rye                                                        Sesamum indicum     sesame                                                     Solanum tuberosum   Irish potatoes                                             Sorghum bicolor (S. vulgare)                                                                       grain sorghum                                              Sorghum dochna                                                                 Spinacia oleracea   spinach                                                    Theobroma cacao     cacao plants                                               Trifolium pratense  red clover                                                 Triticum asetivum   wheat                                                      Vaccinium corymbosum                                                                               blueberries                                                Vaccinium vitis-idaea                                                                              cranberries                                                Vicia faba          tick beans                                                 Vigna sinensis (V. ungulculata)                                                                    cow peas                                                   Vitis vinifera      grapes                                                     Zea mays            Indian corn, sweet corn,                                                       maize                                                      ______________________________________                                    

The new pyridazones may be mixed and applied together with numerous representatives of other herbicidal or growth-regulating active ingredient groups. These combinations extend the spectrum of action, and synergistic effects are achied with some of them. Examples of active ingredients giving, with the new compounds, useful mixtures for a wide variety of applications are given below:

    __________________________________________________________________________      ##STR6##                                                                              R                    R.sup.1                                           __________________________________________________________________________              ##STR7##            NHCH.sub.3                                                 ##STR8##            NHCH.sub.3                                        __________________________________________________________________________      ##STR9##                                                                      R               R.sup.1   R.sup.2                                              __________________________________________________________________________                      ##STR10##                                                                               H       and salts                                    H                                                                                               ##STR11##                                                                               Cl      "                                            H                                                                                               ##STR12##                                                                               F       "                                            H                                                                                               ##STR13##                                                                               CH.sub.3                                                                               "                                            CH.sub.2 OCH.sub.3                                                                              ##STR14##                                                                               H                                                    CH.sub.2 OCH.sub.3                                                                              ##STR15##                                                                               F                                                                     ##STR16##        "                                            __________________________________________________________________________      ##STR17##                                                                     R       R.sup.1 R.sup.2                                                                              R.sup.3     R.sup.4                                      __________________________________________________________________________     H       H.sub.3 CSO.sub.2                                                                      H     n-C.sub.3 H.sub.7                                                                          n-C.sub.3 H.sub.7                            H       F.sub.3 C                                                                              H     C.sub.2 H.sub.5                                                                            C.sub.4 H.sub.9                              H       F.sub.3 C                                                                              H     n-C.sub.3 H.sub.7                                                                          n-C.sub.3 H.sub.7                            H       F.sub.3 C                                                                              H     CH.sub.2CH.sub.2 Cl                                                                        n-C.sub.3 H.sub.7                            H       SO.sub.2 NH.sub.2                                                                      H     n-C.sub.3 H.sub.7                                                                          n-C.sub.3 H.sub.7                            H       F.sub.3 C                                                                              H     n-C.sub.3 H.sub.7                                                                           ##STR18##                                   H.sub.3 C                                                                              H.sub.3 C                                                                              H     H                                                                                           ##STR19##                                   H       F.sub.3 C                                                                              NH.sub.2                                                                             n-C.sub.3 H.sub. 7                                                                         n-C.sub.3 H.sub.7                            H       H.sub.3 C                                                                              H     n-C.sub.3 H.sub.7                                                                          n-C.sub.3 H.sub.7                            __________________________________________________________________________      ##STR20##                                                                            R              R.sup.1    R.sup.2                                       __________________________________________________________________________             ##STR21##     H          CH.sub.3                                              ##STR22##     H          C.sub.2 H.sub.5                                       ##STR23##     CH.sub.3   CH.sub.3                                              ##STR24##     H          CH.sub.3                                       ##STR25##                                                                              R             R.sup.1   R.sup.2                                       __________________________________________________________________________               ##STR26##    H         C.sub.2 H.sub.5                                         ##STR27##    H         C.sub.2 H.sub.5                                ##STR28##                                                                     R                R.sup.2                                                                                R.sup.3                                               __________________________________________________________________________      ##STR29##       H      H     salts, esters, amides                             ##STR30##       CH.sub.3                                                                              H     salts, esters, amides                             ##STR31##       H      H     salts, esters, amides                             ##STR32##       CH.sub.3                                                                              H     salts, esters, amides                            R                R.sup.2                                                                               R.sup.3                                                __________________________________________________________________________      ##STR33##       H      H     salts, esters, amides                             ##STR34##       CH.sub.3                                                                              H     salts, esters, amides                             ##STR35##                                                                     R          R.sup.1          R.sup.2                                            __________________________________________________________________________     i-C.sub.3 H.sub.7                                                                         i-C.sub.3 H.sub.7                                                                                ##STR36##                                         i-C.sub.3 H.sub.7                                                                         i-C.sub.3 H.sub.7                                                                                ##STR37##                                          ##STR38##                                                                     R          R.sup.1          R.sup.2                                            __________________________________________________________________________     n-C.sub.3 H.sub.7                                                                         n-C.sub.3 H.sub.7                                                                               C.sub.2 H.sub.5                                     ##STR39## C.sub.2 H.sub.5  C.sub.2 H.sub.5                                    sec.C.sub.4 H.sub.9                                                                       sec.C.sub.4 H.sub.9                                                                             C.sub.2 H.sub.5                                    n-C.sub.3 H.sub.7                                                                         n-C.sub.3 H.sub.7                                                                               n-C.sub.3 H.sub.7                                  R          R.sup.1          R.sup.2                                            __________________________________________________________________________     C.sub.2 H.sub.5                                                                           C.sub.2 H.sub.5                                                                                  ##STR40##                                          ##STR41## C.sub.2 H.sub.5  C.sub.2 H.sub.5                                    i-C.sub.3 H.sub.7                                                                         i-C.sub.3 H.sub.7                                                                               CH.sub.2CClCHCl                                    n-C.sub.3 H.sub.7                                                                         n-C.sub.3 H.sub.7                                                                               C.sub.2 H.sub.5                                                ##STR42##                                                                      ##STR43##                                                          R                   X         Y  R.sup.1                                       __________________________________________________________________________     CH.sub.3            Cl        Cl Na                                             ##STR44##          Cl        H  CH.sub.3                                       ##STR45##          H         H  H                                             Cl                  Cl        Cl Na                                             ##STR46##          H         CH.sub.3                                                                          CH.sub.3                                       ##STR47##          H         CH.sub.3                                                                          C.sub.2 H.sub.5                                ##STR48##                                                                     R                   X         Y  R.sup.1                                       __________________________________________________________________________      ##STR49##          H         CH.sub.3                                                                          i-C.sub.3 H.sub.7                              ##STR50##          O         CH.sub.3                                                                           ##STR51##                                     ##STR52##          H         CH.sub.3                                                                          Na                                             ##STR53##          H         CH.sub.3                                                                          Na                                             ##STR54##          H         CH.sub.3                                                                          CH.sub.3                                       ##STR55##                                                                     R      R.sup.1  X        R.sup.2                                                                               R.sup.3                                        __________________________________________________________________________     H      C.sub.2 H.sub.5                                                                         SCH.sub.3                                                                               H      C.sub.2 H.sub.5                                H      i-C.sub.3 H.sub.7                                                                       SCH.sub.3                                                                               H      C.sub.2 H.sub.5                                H      CH.sub.3 SCH.sub.3                                                                               H      i-C.sub.3 H.sub.7                              H      i-C.sub.3 H.sub.7                                                                       Cl       H      C.sub.2 H.sub.5                                R      R.sup.1  X        R.sup.2                                                                               R.sup.3                                        __________________________________________________________________________     H      i-C.sub.3 H.sub.7                                                                       Cl       H                                                                                      ##STR56##                                     H      C.sub.2 H.sub.5                                                                         Cl       H      C.sub.2 H.sub.5                                H      C.sub.2 H.sub.5                                                                         Cl       H                                                                                      ##STR57##                                     H      C.sub.2 H.sub.5                                                                         OCH.sub.3                                                                               H      C.sub.2 H.sub.5                                H      i-C.sub.3 H.sub.7                                                                       OCH.sub.3                                                                               H      i-C.sub.3 H.sub.7                              H      C.sub.2 H.sub.5                                                                         Cl       H                                                                                      ##STR58##                                     H      C.sub.2 H.sub.5                                                                         Cl       H                                                                                      ##STR59##                                      ##STR60##                                                                     R             R.sup.1      R.sup.2                                             __________________________________________________________________________     CH.sub.3      CH.sub.3     CH(C.sub.6 H.sub.5).sub.2                            ##STR61##    H                                                                                            ##STR62##                                           ##STR63##    H                                                                                            ##STR64##                                           ##STR65##    H            C.sub.2 H.sub. 5                                    R             R.sup.1      R.sup.2                                             __________________________________________________________________________      ##STR66##    H                                                                                            ##STR67##                                           ##STR68##                                                                                    ##STR69##   CH.sub.2 Cl                                          ##STR70##                                                                                    ##STR71##   CH.sub.2 Cl                                          ##STR72##    CH.sub.2OCH.sub.3                                                                           CH.sub.2 Cl                                          ##STR73##                                                                                    ##STR74##   CH.sub.2 Cl                                          ##STR75##    i-C.sub.3 H.sub.7                                                                           CH.sub.2 Cl                                          ##STR76##    CH.sub.2OC.sub.4 H.sub.9 -n.                                                                CH.sub. 2 Cl                                         ##STR77##                                                                                    ##STR78##   CH.sub.2 Cl                                          ##STR79##    CH.sub.2CH.sub.2OCH.sub.3                                                                   CH.sub.2 Cl                                          ##STR80##                                                                     R             R.sup.1      R.sup.2                                             __________________________________________________________________________     C.sub.2 H.sub.5                                                                              C.sub.2 H.sub.5                                                                              ##STR81##                                          CH.sub.2CHCH.sub.2                                                                           CH.sub.2CHCH.sub.2                                                                          CH.sub.2 Cl                                          ##STR82##    H                                                                                            ##STR83##                                           ##STR84##    H            CH.sub.3                                             ##STR85##    H            CH.sub.3                                             ##STR86##                                                                     X             Y            R                                                   __________________________________________________________________________     Br            Br           H (salts)                                           I             I            H (salts)                                           Br            Br                                                                                           ##STR87##                                           ##STR88##                salts, esters                                         ##STR89##                salts, esters                                         ##STR90##                                                                     R          R.sup.1                                                                          R.sup.2                                                                           R.sup.3                                                        __________________________________________________________________________      ##STR91## H CH.sub.3                                                                          H                                                               ##STR92## H CH.sub.3                                                                          OCH.sub.3                                                       ##STR93## H CH.sub.3                                                                          H                                                               ##STR94## H CH.sub.3                                                                          OCH.sub.3                                                       ##STR95## H H                                                                                  ##STR96##                                                      ##STR97##                                                                      ##STR98##                                                                     R      R.sup.1     R.sup.2                                                                            R.sup.3                                                 __________________________________________________________________________     Cl     CF.sub.3    H   COOH                                                    Cl     Cl          H                                                                                   ##STR99##                                              H      CF.sub.3    Cl  OC.sub.2 H.sub.5                                         ##STR100##                                                                    R      R.sup.1     R.sup.2                                                     __________________________________________________________________________     tert.C.sub.4 H.sub.9                                                                  NH.sub.2    SCH.sub.3                                                   tert.C.sub.4 H.sub.9                                                                   ##STR101## SCH.sub.3                                                    ##STR102##                                                                           NH.sub.2    CH.sub.3                                                     ##STR103##                                                                     ##STR104##                                                                     ##STR105##                                                                    R     R.sup.1                                                                              R.sup.2                                                                           R.sup.3                                                         __________________________________________________________________________      ##STR106##                                                                          sec.C.sub.4 H.sub.9                                                                  H  H                                                               H     CH.sub.3                                                                             H  H (salts, esters)                                               H     sec.C.sub.4 H.sub.9                                                                  H  H (salts, esters)                                                ##STR107##                                                                          tert.C.sub.4 H.sub.9                                                                 H  H                                                                ##STR108##                                                                          tert.C.sub.4 H.sub.9                                                                 H  CH.sub.3                                                        H     tert.C.sub.4 H.sub.9                                                                 H  H (salts, esters)                                                ##STR109##                                                                    X  Y  R                                                                        __________________________________________________________________________     CF.sub.3                                                                          H  CH.sub.3                                                                 H  F  CH.sub.3                                                                  ##STR110##                                                                     ##STR111##                                                                    R        R.sup.1                                                               __________________________________________________________________________     CH.sub.3 C.sub.2 H.sub.5                                                        ##STR112##                                                                             C.sub.2 H.sub.5                                                        ##STR113##                                                                             C.sub.2 H.sub.5                                                        ##STR114##                                                                     ##STR115##                                                                    R  R.sup.1                                                                             R.sup.2   R.sup.3                                                      __________________________________________________________________________     H  n-C.sub.3 H.sub.7                                                                   CH.sub.2CHCH.sub.2                                                                       CH.sub.3                                                     Na n-C.sub.3 H.sub.7                                                                   CH.sub.2CHCH.sub.2                                                                       CH.sub.3                                                      ##STR116##                                                                     ##STR117##                                                                     ##STR118##                                                                    R   R.sup.1                                                                            R.sup.2                                                                              R.sup.3                                                                              R.sup.4                                                    __________________________________________________________________________     H   Cl  NH.sub.2                                                                             Cl    H (salts, esters,                                                              amides)                                                    Cl  Cl  H     Cl    H (salts, esters,                                                              amides)                                                    H   I   I     I     H (salts, esters,                                                              amides)                                                    Cl  H   Cl    OCH.sub.3                                                                            H (salts, esters,                                                              amides)                                                     ##STR119##         (salts, esters, amides)                                     ##STR120##                                                                     ##STR121##                                                                     ##STR122##                                                                     ##STR123##                                                                     ##STR124##                                                                     ##STR125##                                                                     ##STR126##                                                                     ##STR127##                                                                     ##STR128##                                                                     ##STR129##                                                                     ##STR130##                                                                     ##STR131##                                                                     ##STR132##                                                                     ##STR133##                                                                    R.sup.1      R.sup.2                                                                           R.sup.3                                                        __________________________________________________________________________     CH.sub.3     H                                                                                  ##STR134##                                                     ##STR135##  H  i-C.sub.3 H.sub.7                                               ##STR136##  H                                                                                  ##STR137##                                                    R.sup.1      R.sup.2                                                                           R.sup.3                                                         ##STR138##  H                                                                                  ##STR139##                                                     ##STR140##  H  i-C.sub.3 H.sub.7                                               ##STR141##  H  CH.sub.2CCCH.sub.2 Cl                                           ##STR142##  H                                                                                  ##STR143##                                                     ##STR144##  H  CH.sub.3                                                        ##STR145##  H  CH.sub.3                                                        ##STR146##  H                                                                                  ##STR147##                                                     ##STR148##                                                                     ##STR149##                                                                     ##STR150##                                                                     ##STR151##                                                                    R.sub.1   R.sub.2                                                              __________________________________________________________________________      ##STR152##                                                                               ##STR153##                                                           ##STR154##                                                                               ##STR155##                                                           ##STR156##                                                                               ##STR157##                                                           ##STR158##                                                                               ##STR159##                                                           ##STR160##                                                                               ##STR161##                                                           ##STR162##                                                                               ##STR163##                                                          __________________________________________________________________________

It may also be useful to apply the new compounds, either alone or in combination with other herbicides, in admixture with other crop protection agents, e.g., agents for combating pests or phytopathogenic fungi or bacteria. The compounds may also be mixed with solutions of mineral matters used to remedy nutritional or trace element deficiencies, and with mineral fertilizers containing nitrogen, phosphate or potassium.

Application may be effected for instance in the form of directly sprayable solutions, powders, suspensions (including high-percentage aqueous, oily or other suspensions), dispersions, emulsions, oil dispersions, pastes, dusts, broadcasting agents, or granules by spraying, atomizing, dusting, broadcasting or watering. The forms of application depent entirely on the purpose for which the agents are being used; in any case they should ensure a fine distribution of the active ingredient.

For the preparation of solutions, emulsions, pastes and oil dispersions to be sprayed direct, mineral oil fractions of medium to high boiling point, such as kerosene or diesel oil, further coal-tar oils, and oils of vegetable or animal origin, aliphatic, cyclic and aromatic hydrocarbons such as benzene, toluene, xylene, paraffin, tetrahydronaphthalene, alkylated naphthalenes and their derivatives such as methanol, ethanol, propanol, butanol, chloroform, carbon tetrachloride, cyclohexanol, cyclohexanone, chlorobenzene, isophorone, etc., and strongly polar solvents such as dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, water, etc. are suitable.

Aqueous formulations may be prepared from emulsion concentrates, pastes, oil dispersions or wettable powders by adding water. To prepare emulsions, pastes and oil dispersions the ingredients as such or dissolved in an oil or solvent may be homogenized in water by means of wetting or dispersing agents, adherents or emulsifiers. Concentrates which are suitable for dilution with water may be prepared from active ingredient, wetting agent, adherent, emulsifying or dispersing agent and possibly solvent or oil.

Examples of surfactants are: alkali metal, alkaline earth metal and ammonium salts of ligninsulfonic acid, naphthalenesulfonic acids, phenolsulfonic acids, alkylaryl sulfonates, alkyl sulfates, and alkyl sulfonates, alkali metal and alkaline earth metal salts of dibutylnaphthalenesulfonic acid, lauryl ether sulfate, fatty alcohol sulfates, alkali metal and alkaline earth metal salts of fatty acids, salts of sulfated hexadecanols, heptadecanols, and octadecanols, salts of sulfated fatty alcohol glycol ethers, condensation products of sulfonated naphthalene and naphthalene derivatives with formaldehyde, condensation products of naphthalene or naphthalenesulfonic acids with phenol and formaldehyde, polyoxyethylene octylphenol ethers, ethoxylated isooctylphenol, ethoxylated octylphenol and ethoxylated nonylphenol, alkylphenol polyglycol ethers, tributylphenyl polyglycol ethers, alkylaryl polyether alcohols, isotridecyl alcohol, fatty alcohol ethylene oxide condensates, ethoxylated castor oil, polyoxyethylene alkyl ethers, ethoxylated polyoxypropylene, lauryl alcohol polyglycol ether acetal, sorbitol esters, lignin, sulfite waste liquors and methyl cellulose.

Powders, dusts and broadcasting agents may be prepared by mixing or grinding the active ingredients with a solid carrier.

Granules, e.g., coated, impregnated or homogeneous granules, may be prepared by bonding the active ingredients to solid carriers. Examples of solid carriers are mineral earths such as silicic acid, silica gels, silicates, talc, kaolin, Attaclay, limestone, lime, chalk, bole, loess, clay, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate, magnesium oxide, ground plastics, fertilizers such as ammonium sulfate, ammonium phosphate, ammonium nitrate, and ureas, and vegetable products such as grain flours, bark meal, wood meal, and nutshell meal, cellulosic powders, etc.

The formulations contain from 0.1 to 95, and preferably 0.5 to 90, % by weight of active ingredient. Application rates are from 0.1 to 10 kg of active ingredient per hectare.

There may be added to the compositions or individual active ingredients oils of various types, wetting agents or adherents, herbicides, fungicides, nematocides, insecticides, bactericides, trace elements, fertilizers, antifoams (e.g., silicones), growth regulators, antidotes and other herbicidally effective compounds. These agents may be added to the herbicides according to the invention in a weight ratio of from 1:10 to 10:1.

EXAMPLE 2

90 parts by weight of compound 1 is mixed with 10 parts by weight of N-methyl-α-pyrrolidone. A mixture is obtained which is suitable for application in the form of very fine drops.

EXAMPLE 3

20 parts by weight of compound 2 is dissolved in a mixture consisting of 80 parts by weight of xylene, 10 parts by weight of the adduct of 8 to 10 moles of ethylene oxide to 1 mole of oleic acid-N-monoethanolamide, 5 parts by weight of the calcium salt of dodecylbenzenesulfonic acid, and 5 parts by weight of the adduct of 40 moles of ethylene oxide to 1 mole of castor oil. By pouring the solution into 100,000 parts by weight of water and uniformly distributing it therein, an aqueous dispersion is obtained containing 0.02% by weight of the active ingredient.

EXAMPLE 4

20 parts by weight of compound 2 is dissolved in a mixture consisting of 40 parts by weight of cyclohexanone, 30 parts by weight of isobutanol, 20 parts by weight of the adduct of 7 moles of ethylene oxide to 1 mole of isooctylphenol, and 10 parts by weight of the adduct of 40 moles of ethylene oxide to 1 mole of castor oil. By pouring the solution into 100,000 parts by weight of water and finely distributing it therein, an aqueous dispersion is obtained containing 0.02% by weight of the active ingredient.

EXAMPLE 5

20 parts by weight of compound 2 is dissolved in a mixture consisting of 25 parts by weight of cyclohexanol, 65 parts by weight of a mineral oil fraction having a boiling point between 210° and 280° C., and 10 parts by weight of the adduct of 40 moles of ethylene oxide to 1 mole of castor oil. By pouring the solution into 100,000 parts by weight of water and uniformly distributing it therein, an aqueous dispersion is obtained containing 0.02% by weight of the active ingredient.

EXAMPLE 6

20 parts by weight of compound 2 is well mixed with 3 parts by weight of the sodium salt of diisobutylnaphthalene-α-sulfonic acid, 17 parts by weight of the sodium salt of a lignin-sulfonic acid obtained from a sulfite waste liquor, and 60 parts by weight of powdered silica gel, and triturated in a hammer mill. By uniformly distributing the mixture in 20,000 parts by weight of water, a spray liquor is obtained containing 0.1% by weight of the active ingredient.

EXAMPLE 7

3 parts by weight of compound 1 is intimately mixed with 97 parts by weight of particulate kaolin. A dust is obtained containing 3% by weight of the active ingredient.

EXAMPLE 8

30 parts by weight of compound 2 is intimately mixed with a mixture consisting of 92 parts by weight of powdered silica gel and 8 parts by weight of paraffin oil which has been sprayed onto the surface of this silica gel. A formulation of the active ingredient is obtained having good adherence.

EXAMPLE 9

40 parts by weight of compound 1 is intimately mixed with 10 parts of the sodium salt of a phenolsulfonic acid-urea-formaldehyde condensate, 2 parts of silica gel and 48 parts of water. Dilution in 100,000 parts by weight of water gives an aqueous dispersion containing 0.04 wt% of active ingredient.

EXAMPLE 10

20 parts of compound 2 is intimately mixed with 2 parts of the calcium salt of dodecylbenzenesulfonic acid, 8 parts of a fatty alcohol polyglycol ether, 2 parts of the sodium salt of a phenolsulfonic acid-urea-formaldehyde condensate and 68 parts of a paraffinic mineral oil. A stable oily dispersion is obtained. 

We claim:
 1. A pyridaz-6-one compound of the formula ##STR164## where X denotes halogen, R¹ denotes C₁ -C₆ -alkyl, R² denotes H, C₁ -C₆ -alkyl or haloalkyl, and R³ denotes phenyl or cyclohexyl.
 2. A process for combating unwanted plant growth, wherein the plants or the soil are treated with a herbicidally effective amount of a composition containing from 0.1 to 95% by weight of a compound of the formula ##STR165## where X denotes halogen, R¹ denotes C₁ -C₆ -alkyl, R² denotes H, C₁ -C₆ -alkyl or haloalkyl, and R³ denotes phenyl or cyclohexyl.
 3. A compound selected from the group consisting of ##STR166## 